Shunt for carbon brush



May 3, 1960 M. F. SCHMITZ, JR

SHUNT FOR CARBON BRUSH 5 Sheets-s 1 Filed Feb. 8, 1956 Mchae/Fs h Jr INVENTOR y 1960 I M. F. SCHMITZ, JR 2,935,632

SHUNT FOR CARBON BRUSH Filed Feb. 8, 1956 5 SheetsSheet 2 d Mm; I

'M/c/m/ F scam/1 2 Jr:

IN VEN TOR.

BYW a 1960 M. F. SCHMITZ, JR 2,935,632

SHUNT FOR CARBON BRUSH Filed Feb 8, 1956 V 5 Sheets-Sheet 3 \Wv & m

N/chae/ F ScBmF/z Jr.

May 3, 1960 M. FQSCHMITZ, JR

sHuN'r FOR CARBON BRUSH 5 Sheets-Sheet 4 Filed Feb. 8. 1956 I M'c/we/ Sc/mh z J:

IN VEN TOR.

May 3, 1960 M. F. SCHMITZ, JR

SHUNT FOR CARBON BRUSH 5 Sheets-Sheet 5 Filed Feb. 8, 1956 Mi-v/rae/ 50 50117? J/r INVENTOR.

w a n 4 a 3 r 2,935,632 C6 Fate-uteri May 3, 1960 SHUNT FOR CARBON BRUSH Michael F. Schmitz J12, Lemont, Ill. Application February 8, 1956, Serial No. 564,194

22 Claims. (Ci 310-249) This invention relates to carbon brush assemblies for use with electrical generators and motors and particularly to carbon brush assemblies including shunts.

In one type of electrical generators in use today the currentis removed from the commutator by means of a plurality of carbon brushes. The brushes are moimte'dv in holders disposed about the commutator and are connected to the output of the generator. Connection between the output of the generator and the carbon brushes is made by a pair of leads attached toa common con holder, theconnector is formed as an open end U-shaped piece which sometimes works loose thereby causing interruption of'operation of the generator;

Electrical motors also are provided with carbon brushes and shunts to feed electrical energy thereto. The

brushes are disposed in holdersand are spring urged against the cooperating partof the motor. These brush and shuntv assemblies are generally made similar to the brush and shunt assemblies used in generators and de- :scribed above.

It is an important object of the present invention to :provide an improved carbon brush and shunt assembly in which the brush is separable fronrthe shunt whereby the brush can be rapidly and conveniently replaced when worn or broken and alternatively the shunt can be rapidly :and conveniently replaced without replacing the brush should the shunt become worn or defective.

Another object of the invention is to provide a shunt construction of the type set forth which can be readily used with the so-called split brush in which two brush sections are positioned in a single brush holder and are spring urged by a single spring member. V

Still another object of theinvention is to provide a shunt of the type set forth in which the connectors are attached to plugs mounted upon conductive plates :adapted to be disposed against the outer surface of the" brush in electrical contact therewith.

Yet another object of the invention is to provide an :Zimproved separable shunt in which sleeves receiving the conductive leads are mounted upon a conductive plate carrying the pins to be inserted into the brush whereby the leads are protected by the sleeves from contact with the spring urged member to prevent shearing of the leads by the spring urged member. I

Still another object of the invention is to provide an Zimpro'ved separable shunt which can be left connected to the brush holder while the brushes are being changed :and which permits the brushes to be changed without the use of tools.

Yet another object of the invention is to provide an Eimproved shunt of the type set forth in which the leads are securely attached to a plate carrying the plugs to be inserted into' the brushes, the plate being held in operative position by a spring tension'ed member whereby the leads are less likely towork loose from the brush assembly thereby interrupting operation of the associated generator or motor.

Still another object of the invention is to provide in a shunt assembly of the type set forth a curved plate overlying the outer surface of the brush whereby to provide a greater conductive surface between the plate and the and shunt assembly utilizing a split plug;

brush.

A further object of the invention is to provide an improved brush and shunt assembly of the type set forth which provides a longer brush life, which is simple in con-' struction, and which is inexpensive to manufacture.

These and other objects and advantages of the invene tion will be better understood from the following description when taken in conjunction with the accompany ing drawings. In the drawings wherein like reference numerals have been utilized to designate like partsthroughout: '5

Figure l is a partial view in vertical section through: the brush holder for a generator showing a brush andshunt assembly in position therein made in accordance with and embodying the principles of the present invention;

Figure: 2 is an exploded view in perspective oi: the brush andshunt assembly shown in Figure 1;

Figure 3 is an enlarged view in vertical section through the upper end of the brush and shunt assembly of Figure l, the section'beingtaken through one pair of plugs;

Figure 4 is a partial view in vertical section through the brush holder for a reversible motor showing a second embodiment of the present invention; 7

' Figure 5 is an exploded view in perspective of the" brush and shuntassembly of Figure 4;

. Figure 6 is an enlarged partial view in vertical section of the brush and shunt assembly shown in Figures 4 and 5, the section being taken through one set of plugs;

Figure 7 is a View in perspective of a brush and shunt assembly made in accordance with the invention, a singlebrush having been shown;

Figure 8 is a perspective view of another form of the invention; v I Figure 9 is anexploded view of the brush and shunt assembly illustrated in Figure 8;

p Figure 10 is a partial view on an enlarged scale in vertical section through the brush and shunt assemblyof Figure 8- substantially as seen in the'direction of arrows along the line of 10-10 of Figure 8; y 1 Figure 11 is a perspective view of a split pin type of plug useful in the present invention; Figure 12 is a View in horizontal section through the plug of Figure 11 substantially as seen in the direction of" the arrows along the line of l212 of Figure 11;

Figure 13 is a perspective view showing a split brush" Figure 14 is a perspective view of yet another embodiment ota brush and shunt assembly made in accordance with and embodying the principles of the present invention;

Figure 15 is an exploded perspective view of the parts of the brush and shunt assembly of Figure 14;

Figure 16 is an enlarged view in vertical section through the brush and shunt assembly of Figure 14 substantially as seen in the direction of the arrows along the line 16- 16 of Figure 14} Figure 17 is a partial view in vertical section through the brush holder for a reversible motor showing a further embodiment of the present invention incorporated therein;

Figure 18 is an exploded view in perspective of the brush and shunt assembly of Figure 17; and

Figure 19 is an enlarged partial view in vertical section of the brush and shunt assembly shown in Figures 17 and 18', the section being taken through one set of plugs.

1 ewe v v .11:

Referring to Figures 1, 2 and 3 of the drawings there is shown a brush and shunt assembly generally designated by the numeral 26 made in accordance with and embodying the principles of the present invention. The brush and shunt assembly 20 has been illustrated as a split brush assembly including a pair of brush members 22 and 24 interconnected by a shunt generally designated by the numeral 26. The brush and shunt assembly 20 is shown mounted in and supported by a brush holder segment generally designated by the numeral 23. Brush holder segment 28 includes a pair of walls 30 and 32 having parallel inner faces which provide a guideway for brush members 22 and 24. A brush tension member 34- urges the brush members 22 and 24 against the associated commutator and is held in operative position by a spring 36 mounted upon a shaft 38. Brush members 22 and 24 are generally rectangular in cross section and are provided with a pair of spaced apart rectangularly shaped side surfaces.

As may be best seen in Figures 1 and 3 the top surfaces 40 and 42 of brush members 22 and 24, respectively, are disposed at an angle with respect to the parallel rectangular sides of the brush members. More specifically, top 40 forms an acute angle with rectangular side 44 of brush members 42 of approximately 75 degrees and top 42 of brush members 24 forms an angle of approximately 75 degrees also with rectangular side 46. The lower ends 48 and 50 of brush members 22 and 24, respectively, also form an acute angle with sides 44 and 46, respectively. Lower ends 48 and 56 make contact with the surface of the commutator and holder 28 maintains the longitudinal axes of brush members 22 and 24 inclined at an acute angle with respect to a tangent to the commutator at the point of contact with brush members 22 and 24.

Theupper surfaces 46 and 42 are suitably apertured to receive plugs which form a part of shunt 26. More specifically, upper surface 40 of brush member 22 is provided with a pair of holes 52 and 54 which have the axes thereof disposed parallel to the plane of side 44 and upper surface 42 is provided with a pair of holes 56 and 58.

The shunt 26 includes a pair of solid plugs 60 and 62 which are adapted to be inserted in and received by holes 52 and 54, respectively. Plugs 60 and 62 are mounted upon a plate 64 and have formed integral therewith above plate 64 sleeves 66 and 68, respectively. Sleeves 66 and 68 are adapted to receive a pair of flexible leads 7% and 72, respectively, which are attached at the other ends thereof to a connector 74.

A second set of plugs 76 and 78 mounted upon a plate 80 is provided to be inserted in apertures 56 and 58, respectively, of brush member 24. Plugs 76 and 78 are provided with integral sleeves 82 and 84, respectively, which are adapted to receive flexible leads 86 and 88, respectively. Leads 86 and 88 are also attached to the connector 74.

Referring to Figure 3 of the drawings the construction ofplugs 60 and 76 and associated parts will be described more fully. Plug 60 is formed solidand substantially fills hole 52 and forms a tight fit therewith. The upper end of plug 60 extends through an aperture in plate 64 and is formed integral with sleeve 66 which has a diameter slightly greater than the diameter of plug 66. The axis of plug 66 is disposed at an acute angle of approximately 75 degrees with respect to plate 64 so that plate 64 can lie flat upon upper surface 46 when plug 60 is inserted in hole 52. Any suitable means such as an induction weld 96 is used} tosecure plug 60 and the associated sleeve 66 to plate 64.

Sleeve 66 is provided with an elongated recess 92 which receives the lower end of flexible lead 70. Sleeve 66 is deformed or crimped inwardly as at 94 to secure lead 70 to sleeve 66. The upper end of sleeve 66 is chamfered as at 96 so that no sharp edges are present to Wear away or break lead 70 during use thereof.

Plug 76 is also formed substantially cylindrical and fits tightly into hole 56. An aperture in plate 80 receives pin 76, the axis of pin 76 being disposed at an acute angle of approximately degrees with respect to the surface of plate 80. Sleeve 82 is formed integral with plug 76 and has a diameter greater than plug 76. Any suitable fastening means such as an induction weld 98 secures plug 76 and the integral sleeve 82 to plate 80. A cylindrical recess 196 is formed in sleeve 82 to receive the lower end of lead 86. Sleeve 82 is deformed or crimped inwardly at 102 firmly to secure lead 86 to sleeve 82. The upper end of sleeve 82 is chamfered as (t 164 to remove any sharp edges which might end to wear or break lead 86.

t is to be noted that the width of plate 60 is slightly less than the width of upper surface 46 and similarly the width of plate 30 is slightly less than the width of upper surface 42. Likewise the lengths of plates 64 and are slightly less than the lengths of the associated brush upper surfaces 40 and 42, respectively. By making the plates 64 and 80 slightly smaller in each dimension than the associated surfaces 45) and 42, respectively, the plates will not interfere with the walls of the associated brush holder during use.

Plate 64 is deformed upwardly in the center thereof and is widened to provide an overlying extension 106 which is adapted to overlie the upper surface of plate 80 between sleeves 82 and 84. It is upon the upper surface of extension 106 that the spring urged member 34 rests during operation. This arrangement insures that equal pressure is applied to both brush members 22 and 24 and also prevents member 34 from lodging between plates 64 and 80. By disposing the plates 64 and 80 and the associated upper surfaces 40 and 42 at an acute angle of approximately 75 degrees with respect to the longitudinal axes of brush members 48 and 50, member 34 can perform its function and follow the brush members 48 and 50 readily with a minimum of spring pressure applied thereto.

' The leads 70, 72, 86 and 88 are all attached to the common connector 74. Connector 74 is preferably formed of sheet metal wrapped around the ends of the leads and crimped thereto as at 168. A circular aperture 110 is formed in one end of connector 74 and is adapted to be attached to the frame of brush holder 28 by means of a bolt 112. V

A new set of brush members 22 and 24 can be readily installed by retracting the spring urged member 34 upwardly and to the left as viewed in Figure l. The shunt 26 can be readily removed from the brush members 22 and 24 without the use of tools and without removing connector 74 from the holder 28. A new set of brush members 22 and 24 is then inserted in brush holder 28 and plugs 60, 62, 76 and 78 inserted in the holes therein. Member 34 is then released to engage extension 166 and the brush is in condition for immediate use. The replacement of the brush members 22 and 24 can be quickly and simply accomplished without the use of any tools. During the replacement the upper surfaces 40 and 42 of the brush members are protected from damage by accidental release of the member 34 by plates 64 and 80.

During operation member 34 cannot shear the leads 70, 72, 84 and 88 because the leads are protected by the sleeves 66, 68, 82 and 84.

The plugs and their associated sleeves and the plates and the leads are all formed of electrical conductive materials such as brass or copper. A good path for flow of electrical current is provided directly from the brush members 22 and 24 upwardly to the plugs and through the plugs directly to the sleeves and the leads 70, 72, 86 and 88.

Referring now to Figures 4, 5 and 6 in the drawings there is shown a brush assembly made in accordance with and embodying the principles of the present invention, the brush assembly being one particularly adapted to be used in a reversible traction motor. In reversible traction motors the brush must be positioned with the axis thereof disposed normal to the surface of the rotor. To this end ages-sees of carbon brush members. 120 and 122 cooperating with i a rotor 124. The carbon brush structure shown isalso of the splitbrush construction.

Referring particularly to Figures 5 and 6 of the drawings, it will be seen that the upper surfaces 126 and 128 of brush members 120 and 122, respectively,' are curved and when placed in juxtaposition form a continuous curve. A pair of holes 130 and 132 is provided in upper surface 126 and a similar pair of holes 134 and 136 is provided inupper surface 123.

A shunt assembly generally designated by the numeral 138 interconnects the upper ends of brush members 120 and 122 to the brush holder 114. Shunt assembly 138 includes a pair of curved plates 146 and 142. Plate 140 carries a pair of plugs 144 and 146 which are adapted to be inserted in holes 130 and 132, respectively, in brush member 120. Formed integral with plugs 134 and 136 are sleeves 148 and 1556 which receive and grip a pair of flexible leads 152 and 154, respectively; 7

Plate 142 carries a pair of plugs 156 and 158 which are adapted to be inserted in and received by holes 134 and 136 in brush member 122. Formed integral with plugs 156 and 158 are sleeves 160 and 162, respectively, which receive and form a connection with a pair of flexible leads 164 and 166. Leads 152,154, 164 and 166 areall attached to a common connector 168.

Referring specifically to Figure 60f the drawings, a more detailed description'of the construction of plugs 144 and 166 and their associated parts will be given. The axes of the holes 136 and 134 are disposed substantially parallel to the sides of brush members 129 and 122. As has been pointed out above, the upper surfaces 126 and 126 form a continuous curvewith the high point of the curve at the point of contact between brush members 120 and 122. Plate 146 iscurved convexly as viewed from the top to conform to the curve of upper surface 126. The width of plate 149 is less than the width of brush member 126 and the length of plate 140 is less than the length of upper surface 126 wherebylall edges of plate 1-46 are disposed inwardly from the edges of upper surface 126. Plate 142 similarly is ctu'ved convexly when viewed from top and has the edges thereof recessed from the edges of upper surface 128. By recessing the edges of plates 14% and 142, any interference of the plates with walls of the associated brush holder during use is prevented.

I Plugs 144 and 156 substantially fill and form a snug fit with the walls of associated holes 130 and 134, respectively. Plug 144 extends upwardly and through an aperture in plate 14%? and is formed integral with sleeve 143. Sleeve 14% has an external diameter-greater than,

plug 144 and, therefore, rests upon the upper surface of plate 1 :6. Any suitable means such as an induction- Weld 171 is provided to interconnect sleeve 148and plug 144 with plate 140. A substantially cylindrical hole is Referring against) Figure 4 of the drawings, it will seen that a spring urged member 184 contacts plates 140 and 142 and urges the plates and the associated brush members 121) and 122 downwardly under the action of a spring 186. By curving plates 146 and 142'as described,

tions of the brushes.

and make contact with the plates 140 and 142 in all posi- This also promotes even wear of the brushes and gives a greater conductive surface between the plates and the brushes. plates 141) and 142 also grip the brush members 120 and 122 more firmly. I

The outer ends of the leads 152, 154, 164 and 166 are all connected to the common connector 163. Connector 168 wraps around and receives the ends of the flexible leads and is fastened thereto by a crimped portion 188. A circular aperture 190 is formed in connector 168 and permits attachment of connector 168 to the brush holder lldby means of a bolt 192.

The plates 140 and 142, the plugs 144-, 146, 156 and 158, the leads 152, 154, 164, and 166 and the connector 168 are all formed of electrical conductive materials such as copper or brass. The brush members 120 and 122 can be quickly removed and detached from the shunt 138 by withdrawing the plugs 144-, 146, 156 and 158 from their respective holes in the brush members 126 and 122. Thereplacement of the brush members 121) and 122 can be performed without the use of any tools.

in Figure '7 there is shown a single brush provided with a shunt made in accordance with and embodying the principles of the present invention. More specifically,. a single brush 194is shown which is provided with a pair of holes receiving plugs 1% and 198. Plugs 196 and 198 are connected to a plate 261) by induction welds at points2tl2 and have formed integral therewith enlarged sleeves 264 and 266, respectively. Slceves204 and 206 receiveand grip flexible leads 268 and 210,: respectively, which are connected to a commonconnector 212. Leads 208 and 210 are held in their respective sleeves by crimping as at 214 and 216 and the upper ends of the sleeves are chamfered as at 218 and 220.

Connector 212 is attached to the other ends of the leads. 2% and 210 by'crirnping as at 222. A circular aperture 224 in connector 212 permits attachment to a point of electrical contact. The dimensions of plate 260 are slightly lessthan the dimensions of the adjacent end of brush 194 so that the edges of plate 260 are set back from the edges of brush 194. This prevents interference in use between plate 209 and the walls of the brush holder receiving brush 194.

There is shown in Figures '8, 9 and 10 of the drawings yet another embodiment of the present invention applied to a split brush installation. A pair of brush members 230 7 and 232 is provided, the brushes 231) and 232 being interconnected by a shunt assembly generally designated by the" numeral 234. Shunt assembly 234 includes a pair ofplates formed in sleeve 14% to receive one end of the flexible lead 152. At one point in its wall, sleeve 148 is deformed or crimped inwardly as at 172 to form a connection be tween lead 1552 and sleeve 143. The upper end of sleeve 148 is chamfered as at 174 to ensure that there are no sharp corners against which lead 152 might be pressed during operation.

Flag 156 is also generally cylindrical in shape and extends upwardly through an aperture in plate 142. Sleeve 16%- is formed integral with plug 156 and has an outer diameter greater than the diameter of plug 156. A cylindrical recess or, hole 116 is formed in sleeve 160 to receive one end of the flexible lead 164. Lead 164 is held in position within sleeve 161 by means of a deformation or crimp 173 in the wall of sleeve 160. An induction weld 166 firmly secures sleeve 160 and plug 156 to plate 142. The upper end of sleeve 160 is chamfered as at 182.

236and 238 which overlie the outer ends of brush members 236 and 232. Each of brush members 230 and 232 is provided with a pair of sockets or holes, brush member 236 being provided with holes 240 and 242 and brush member 232 being provided with holes 244 and 246. Positioned in the holes in brushes 230 and 232 are sleeves 248, 250, 252 and 254 which are positioned in holes 241 242, 244 and 246, respectively. The sleeves 248 and 250 are adapted to receive plugs 256 and 258 mounted on plate 236 and sleeves 252 and 254' are adapted to receive plugs'260 and 262 mounted on a plate 233. Con

T he curved contact formed hollow and are provided with slits 274 and 276, respectively, which give resiliency to the plugs. The plugs extend upwardly through apertures in their associated plates and suitably secured thereupon as by welding at points 278 and 280. The lower end of the lead 264 extends into the upper end of plug 256 and is connected thereto by inward crimping as at 282. The lower end of flexible leads 268 is similarly received in the upper end of hollow plug 26% and is secured thereto by crimping as at 2 54. It is to be noted also that the edges of plates 236 and 233 are set back from the associated edges of the brush members 23% and 232 so that the plates 236 and 233 will not interfere with the walls of an associated brush holder during use.

In certain installations an especially tight fit of the plugs 256, 25%, 260 and 262 in the associated sleeves may be desirable. In such cases the plugs in each set, for example plugs 25d and 258 may be set inwardly toward each other slightly so that the centers thereof are spaced apart a distance less than the centers of sleeves 248 and 25%. This provides an increased tension in the plugs whereby to give a tighter fit.

The construction shown in Figures 8, 9 and 10 and particularly the use of the sleeves 248, c, 252 and 254 in the brush members is particularly valuable when the thickness of brush members 23% and 23?. is small. The sleeves provide reinforcement at the point at which holes 246, 242, 244 and 246 are formed in the brush members thereby preventing breaking away, or chipping or cracking of the brush members when the plugs are inserted or during use.

There is shown in Figures ii and 12 of the drawings a form of plug which is useful in certain constructions, the plug generally being designated by the numeral 286. Plug 286 has a circular portion 28?: from which depend four relatively flexible prongs 2%. A hollow sleeve 292 is formed integral with the solid portion 288 and is provided with an aperture .294 therein to receive a lead.

In Figure 13 is shown yet another form of plug useful in the present invention, the plugs being generally designated by the numeral )6 and being shown applied to a split brush assembly. Brush members 298 and 300 are provided having sockets or holes 302 and 304 formed therein. Plugs 2% are of the so-called split pin type and are provided with a pair of spaced apart yieldable prongs 3% adapted to be received in holes 302 and 364. Plugs 2% are mounted upon plates 308 on which are mounted tubular connectors 316. Attached to the tubular connectors 33.0 are flexible leads 312.

In Figures 14, 15 and 16 there is shown a single brush construction in which a shunt assembly similar to that illustrated in Figures 8, 9, and 10 has been applied. More particularly, there has been provided a carbon brush 314 in wh ch are formed a pair of sockets or holes 316 and 318. Disposed in holes 316 and 318 are sleeves 320 and 322. The shunt assembly which is generally designated by the numeral 324 includes a plate 326 upon which are mounted hollow plugs 328 and 330. Preferably plate 326 has the edges thereof recessed from the edges of brush 314 so that plate 326 will not interfere with walls of the associated brush holder during use.

- Referring to Figure 16 it will be seen that the plug 323 which is formed identical with plug 334) is provided with a plurality of slits 332 formed therein to provide increased resilience. The upper end of plug 328 passes through an aperture in plate 32.6 and is fixed thereto as by induction welding at point 334. The hollow upper end of plug 328 receives the lower end of the flexible lead 336 and lead 336 is attached thereto by crimping plug 323 as at 3323. Plug 330 similarly receives the lower end of a flexible lead 340 and grips lead 340 as by being crimped as at 342. The other ends of leads 336 and 34% are connected together and to a connector 344 which is of the open ended or U-shaped type.

There is shown in Figures 17, 18 and 19 of the drawings a modified form of brush assembly for use in a reversible traction motor. The brush assembly is shown installed in a brush holder in Figure 17. The brush holder is generally designated by the numeral 350 and is provided with a brush receiving aperture or guideway having a pair of walls 332 and 354. Walls 332 and 354 receive and guide a pair of carbon brush members 356 and 358 cooperating with a rotor 36%.

As maybe best seen in Figures 17 and 18, the upper surfaces 362 and 364 of brush members 356 and 358, respectively, are formed flat and are disposed at substantially right angles to the various intersecting surfaces thereof. A pair of holes 365 and 353 is provided in the upper surface 362 and a similar pair of holes 370 and 372 is provided in upper surface 364.

The shunt assembly, generally designated by the numeral 374 interconnects the upper ends of the brush members 356 and 358 and the brush holder 350. The shunt assembly 374 includes a pair of plate members 376 and 378. Referring specifically to Figure 19 of the drawings, it will be seen that plate members 376 and 378 are provided with fiat surfaces 389 and 332, respectively, which are adapted to be positioned against the upper surfaces 362 and 354, respectively, of brush members 356 and 358. A short upstanding wall 334 connects with surface 380 and also connects with a curved upwardly extending surface 336. Side 332 similarly is connected with a perpendicular short surface 338 which in turn connects with an upwardly curving surface 390. Surfaces 386 and 3% form a continuous curve convex in shape for a purpose which will be more fully described hereinafter.

Plate member 376 carries a pair of plugs 392 and 394 which are adapted to be inserted in holes 365 and 368, respectively, in brush member 356. Sleeves 3% and 398 are formed integral with plugs 392 and 394 and receive and grip a pair of flexible leads 4% and 432, respectively. Plate member 373 similarly carries a pair of plugs 4G4 and 4% adapted to be inserted in and received by holes 379 and 372 in brush member 358. Formed integral with plugs 4% and 4% are sleeves 498 and 4155, respectively. Sleeves can and 410 receive and flolrrn a connection with a pair of flexible leads 412 and Leads 4%, 432, 4. 12 and 41.4 are all attached to a common connector 415. More specifically, connector 416 is crimped as at 413 to retain the leads therein. An aperture 426 is formed in connector 416 and is adapted to receive a bolt 422 therethrough which in connection with a washer 424 attaches connector 416 to the brush holder 35%.

Referring specifically to Figure 19 of the drawings, a more detailed description of the construction of plugs 3/2 and 432 and their associated members will be given. The axes of the holes 366 and 37b are disposed substantially parallel to the sides of brush members 356 and 3.53 and substantially perpendicular to the plane of the top surfaces 362 and 36-4. The width of plate member 376 is less than the width of brush member 356 and the length of plate member 37-5 is less than the length of upper surface 362 whereby all edges of plate member 376 are disposed inwardly from the edges of upper surface 362. Plate member 378 similarly has the edges thereof recessed from the edges of upper surface 364. By recessing the edges of plate members and 378. any interference of these members with the walls of the associated brush holder during use is prevented.

Plugs 332 and substantially fill and form a snug lit with the walls of associated holes 356 and 37%, respectively. Plug 332 extends upwardly and through an aperture in plate member 37% and is formed integral with sleeve 3%. Sleeve 3% has an external diameter greater than plug 392 and therefore rests upon the upper curved surface 336 of plate member 376. Any suitable means such as an induction weld 426 is provided to intercon- 'jects and advantages set forth above.

assumes nect sleeve 396 with plate member 376. substantial ly cylindrical hole is formed in sleeve 396 to receive one Sleeve 396 is deformed end of the flexible lead are. or crimped inwardly as. at 428 to form a connection between lead 409 and sleeve 396. The upper end of sleeve 3% is charnfered as at 43d to ensurethat there are no sharp corners against which lead 400 may be pressed during operation. '1

'Plug 4&4 isgenerally cylindrical in shape and extends upwardly through an aperture in plate member 378 Sleeve 408 is formed integral with plug and has an w is a a" second pairof plugs mounted upon said second plate, the'ax'es' of said second pair of plugs beingdisposed parallel to each' other and at an acute angle with respect to the plane of second said plate, a second pair of leads each having one end thereof connected to one of said ;second pair of plugs, said first plate having an extension formedfithereonbetween said first pair of plugs and extending outwardly therefrom and adapted to overlie said psecond plate between said second pair of plugs when in outer diameter greater than the diameter of plug tfiaf A cylindrical recess or hole 432 is formed in sleeve 468 to receive one end of the flexible lead 412. Lead 412 isheld in position within sleeve 4'38 bymeans of a demembers 376 and 378 and urges the plate members and the associated brush members 356 and 358 downward ly under the action of a spring. 442. By curving the upper surfaces 386 and 390 of plate members 376 and 378 as described, the spring urged member 449 can follow the brushes and make contact with the plate members 376 and 373 in all positions of the brushes. This promotes even Wear of the brushes.

The plate members 376 and 378, the plugs 392 and Q 334, 4:34 and 406, and the connector '416 areall formed of electrically conductive materials such as copper or brass. The brush members 356 and 358 can be quickly removed and detached from the shunt 374 by withdrawing the plugs 392, 394, 404 and 406 from their respective holes in the brush members 356 and 358. The re-' placement of the brush members 356 and 358 can be performed without the use of any tools. Shorter brush members 356 and 358 can be used because of the wedge shape of plate members 376 and 378 and still obtain the same amount of service therefrom. This together with the flat top surfaces 362 and 364 results in a substantial saving in the cost of brush members 356 and 358.

This application is a continuation-in-part of my 'copending application, Serial No. 492,841, filed March 8, 1955, for Shunt Brush, now abandoned.

It will be seen that there has been provided a shunt and a shunt and brush assembly whichfulfill all the ob- Although certain preferred embodiments of the invention have been given for purposes of illustration, it is to be understood that various changes and modifications can be made'therein without departing from the spirit and scope. thereof. Ac

cordingly, the invention is to be limited only as set forth in the following claims.

I claim: I 1 l. A shunt comprising a first plate, a first pair of plugs mounted upon said first plate in spaced apart relation,

21 first pair of leads each having one end thereof connected to one of said first pair of plugs, a second plate,

a second pair of plugs mounted upon said second plate in spaced apart relation, a second pair of leads each having one end thereof connected to one of said second pair of plugs, said first plate having an extension formed there on between said first pair of plugs and extending outwardly therefrom and adapted to overlie said second plate between'said second pair of plugs when in operative position, and a connector interconnecting the other ends of said leads. v I

2. A shunt comprising a first plate, a first pair of plugs mounted upon said first plate, the axes of said first pair a second pair of leads each having one end thereof conof plugs being disposed in parallelism with each other and at an acute angle with the plane of said first plate,

a first pair of leads each having one end thereof con-' nectedtoms of said first pair'of plugs, a second plate,

operative position, and a connector interconnecting the other ends of said leads.

3. A shunt comprising a first plate having a pair of spaced apart apertures therein, a first pair of plugs each extending through one of said apertures in said first plate, the axes of said first pair of plugs being disposed in parallelism at an acute angle with respect to the plane of said first plate, each of said first pair of plugs having a first hollow sleeve thereon,each of said first sleeves having an external diameter greater than the diameter of said first plugs and being positioned on the sideof said first plate opposite said first plugs and secured thereto, a first pair of leads each having one end thereof disposed in one of said first hollow sleeves, each of said first hollow sleeves being crimped about the associated lead to form a connection therewith, a second plate having a pair of spaced apart apertures formed therein, a second pair of plugs each'extending through one of the apertures in said second plate, theaxes of said second pair of plugs being disposed in parallelism and at an acute angle with respect to the plane of said second plate, said second pair of plugs each having a second hollow sleeve thereon and positionedon the side of said plate opposite said ond sleeves, said second sleeves being crimped about the; associated lead to form a connection therewith, said first platelhaving an extension formed thereon between said first pair of sleeves and extending outwardly therefrom and adapted to overlie said second plate between said second pair of sleeves in operative position, and a common connector interconnecting the other ends of said leads.

4. A shunt for use with a split brush including a pair ofbrush members each having a pair of spaced apart apertures formed in one face thereof, comprising a first plate adapted to'o'verlie the face of an associated brush member andhaving dimensions such that the edges thereof are set back from the edges of the face, a first pair of plugs mounted upon said first plate in spaced apart relation and adapted to be inserted in the holes in the associated brush member, a first pair of leads each having one end thereof connected mom of said first pair of plugs, a second plate adapted to overlie the face of another associated brush member and having dimensions such that the edges thereof are set back from the edges of the associated face, a second pair of plugs mounted upon said second plate in spaced apart relation and adapted to beinserted in the holes in the associated face,

nected to oneofsaid second pair of plugs, said first plate having an extension formed thereon between said first pair of plugs and extending outwardly therefrom and adapted to overlie said second plate between said second pair of plugs when said plugs are inserted in said brush members, and a connector interconnecting the other ends of said leads.

- 5'. 'A shunt for use with a split brush including a pair of brush members eachhaving a pair of holes formed in one face thereof, the axes of said holes being disposed in parallelism with eachother and at an acute angle with the plane of-the associated face, comprising a first plate adapted to overliertheface of an associatedbrush membet and having dimensions'such that the edges thereof are set back from the edges of the associatedface, a first pair of plugs mounted upon said first-plate and being adapted to be inserted in the holes in the associated face, the axes of said first pair of plugs being disposed in parallelism with each other and at an acute angle with the plane of said first plate so that said first plate lies fiat upon the associated face when said plugs are inserted in the associated holes, a first pair of leads each having one end thereof connected to one of said first pair of plugs, a second plate adapted to overlie the face of another associated brush member and having dimensions such that the edges thereof are set back from the edges of the associated face, a second pair of plugs mounted upon said second plate in spaced apart relation and adapted to be inserted in the holes in the associated face, the axes of said second pair of plugs being disposed parallel to each other and at an acute angle with respect to the plane of said second plate so that said second plate lies flat upon the associated face when said second pair of plugs is inserted in the associated holes, a second pair of leads each having one end thereof connected to one of said second pair of plugs, said first plate having an extension formed thereon between said first pair of plugs and extending outwardly therefrom and adapted to overlie said second plate between said second pair of plugs when in operative position, and a connector interconnecting the other ends of said leads.

6. A shunt for use with a split brush including two brush members each having a pair of holes formed in one face thereof, said faces being convexly curved to form a continuous curve, comprising a first curved platecurved to lie upon the face of an associated brush member, a first pair of plugs mounted upon said first plate in spaced apart relation and adapted to be inserted in the holes in the associated face, a first pair of leads each having one end thereof connected to one of said first pair of plugs, a second curved plate curved to lie upon the face of another associated brush member, a second pair of plugs mounted upon said second plate in spaced apart relation and adapted to be inserted in the holes in the associated face, a second pair of leads each having one end thereof connected to one of said second pair of plugs, and a connector interconnecting the other ends of said leads.

7. A shunt comprising a first plate member, a first pair of plugs mounted upon said first plate member, the axes of said first pair of plugs being disposed in parallelism with each other and substantially perpendicular to the adjacent surface of said first plate member, the opposite surface of said first plate member being curved, a first pair of leads each having one end thereof connected to one or" said first pair of plugs, a second plate member, a second pair of plugs mounted upon said second plate member, the axes of said second pair of plugs being disposed parallel to each other and perpendicularly to the adjacent surface of said second plate member, the opposite surface of said second plate member being curved, said opposite surface of said first and second plate members forming arc of a continuous curve, a second pair of leads each having one end thereof connected to one of said second pair of plugs, and a connector electrically interconnecting the other ends of said leads.

8. A shunt for use with a split brush including a pair of brush members each having a pair of holes formed in one face thereof, the axes of said holes being disposed in parallelism with each other and substantially perpendicular to the plane of the associated face, comprising a first plate member adapted to overlie the face of an associated brush member and having dimensions such that the edges thereof are set back from the edges of the associated face, a first pair of plugs mounted upon said first plate member and being adapted to be inserted in the holes of the associated face, the axes of said first pair of plugs being disposed in parallelism with each other and substantially perpendicular to the adjacent surface of said first plate member, the opposite surface of said first plate member being curved, a first pair of leads each having one end thereof connected to one of said first pair of plugs, a second plate member adapted to overlie the face of another associated brush member and having dimensions such that the edges thereof areset back from the edges of the associated face, a second pair of plugs mounted upon said second plate member in'spaced apart relation and adapted to be inserted in the holes in the associated face, the axes of said second pair of plugs being disposed parallel to each other and perpendicular to the plane of the adjacent surface of said second plate member, the opposite surface of said second plate member being curved and forming with the curved surface of said first plate member arcs of a continuous curve, a second pair of leads each having one end thereof connected to one of said second pair of plugs, and a connector electrically interconnecting the other ends of said leads. i

9. A shunt comprising a first plate, a first plug mounted upon said first plate, a first lead having one end thereof connected to said first plug, a second plate, a second plug mounted upon said second plate, a second lead having one end thereof connected to said second plug, and an ex-'- tension formed on said first plate and extending outwardly therefrom and adapted to overlie said second plate when in operative position.

10. A shunt as set forth in claim 9, wherein each plug has a hollow sleeve connected thereto and disposed on the side of the associated plate opposite the associated plug and receiving the associated lead and being crimped thereabout to form a mechanical and electrical connection therewith.

11. A shunt for use with a split brush including a pair of brush members each having an aperture formed in one face thereof, said shunt comprising a first plate adapted to overlie the face of an associated brush member and having dimensions such that the edges tlereof are set back from the edges of the associated face, a first plug mounted upon said first plate and adapted to be inserted in the hole in the associated brush member, a first lead having one end thereof connected to said first plug, a second plate adapted to overlie the face of another associated brush member and having dimensions such that the edges thereof are set back from the edges of the sociated face, a second plug mounted upon said second plate and adapted to be inserted in the hole in the associated face, a second lead having one end thereof connected to said second plug, and an extension formed on said first plate and extending outwardly therefrom and adapted to overlie said second plate when in operative position.

12. A shunt comprising a first plate, a first pair of plugs mounted upon said first plate in spaced apart relation, a first pair of leads each having one end thereof connected to one of said first pair of plugs, a second plate, a second pair of plugs mounted upon said second plate in spaced apart relation, a second pair of leads each having one end thereof connected to one of said second pair of plugs, and an extension formed on said first plate and extending outwardly therefrom and adapted to overlie said second plate between said second pair of plugs when in operative position.

13. A shunt comprising a first plate, a pair of plugs mounted upon said first plate in spaced apart relation and extending outwardly from one side thereof, a hollow sleeve for each of said plugs and connected thereto and extending from said first plate on the side thereof opposite said first pair of plugs, a first pair of leads each having one end thereof received in one of said first sleeves, said first sleeves being crirnped about the associated first lead to form a mechanical and electrical connection therewith, a second plate, a second pair of plugs mounted upon said second plate inspaced apart relation and extending therefrom on one side thereof, a hollow sleeve for each of said second plugs and connected thereto and extending from said second plate in a direction opposite to said second plugs, a second pair of leads each having one end thereof received in one of said second sleeves, said second sleeves being crimped about said second leads to form a mechanical and electrical connection therewith, an extension formed on said first plate and extending outwardly therefrom and adapted to overlie said second plate between said second pair of plugs when in operative position, and a connectorinterconnecting the other ends of said leads.

14. A shunt'comprising a first plate, a first plug mounted upon said first plate and extending out of one surface of said first plate, the opposite surface of said first plate being curved, a first lead having one end thereof connected to said first plug, a second plate, a second plug mounted upon said second plate and extending out of one surface thereof, the opposite surface of said second plate being curved, said opposite surfaces of said first and second plates forming arcs of a continuous curve, and a second lead having one end thereof connected to said second plug.

15. A shunt as set forth in claim 14, wherein each plug has a hollow sleeve connected thereto and disposed on the side of the associated plate opposite the associated plug and receiving the associated lead and being crimped thereabout to form a mechanical and electrical connection therewith. V

16. A shunt for use with a split brush including a pair of brush members, each having a hole formed in one face thereof, said shunt comprising a first plate adapted to overlie the face of an associated brush member and having dimensions such that the edges thereof are set back from the edges of the associated face, a first plug mounted upon said first plate and extending from one face thereof, the opposite face of said first plate being curved, a first lead having one end thereof connected to said first plug, a second plate adapted to overlie the face of another associated brush member and having dimensions such that the edges thereof are set back from the edges of the associated face, a second plug mounted upon said second plate and extending from one face thereof and adapted to be inserted in the hole in the face of the associated brush member, the opposite surface of said second plate member being curved and forming with the curved surface of said first plate member arcs of a continuous curve, and a second lead having one end thereof connected to said second plug.

17. A shunt comprising a first plate, a first pair of plugs mounted upon said first plate, the axis of said first pair of plugs being disposed in parallelism with each other and substantially perpendicular to the adjacent surface of said first plate, the opposite surface of said first plate being curved, a first pair of leads each having one end thereof connected to one of saidfirst pair of plugs, a second plate, a second pair of plugs mounted upon said second plate, the axis of said second pair of plugs being disposed parallel to each other and substantially perpendicular to the adjacent surface of said second plate, the opposite surface of said second plate being curved and forming with said opposite surface of said first plate arcs of a continuous curve, and a second pair of leads each having one end thereof connected to one of said second pair of plugs.

18. A shunt comprising a first plate, a first pair of plugs mounted upon said first plate and extending from one surface thereof, the axis of said first pair of plugs being disposed in parallelism with each other and substantially perpendicular to said one surface of said first plate, the opposite surface of said first plate being curved, a first hollow sleeve for each of said first plugs and connected theretoand extending outwardly from said op posite surface,'a first pair of leads each having one end" thereof received 'in one of said first sleeves, said first sleeves being crimped about the associated first lead to form a mechanical and electrical connection therewith, a second plate, a second pair of plugs mounted upon said second plate and extending from one surface thereof, the axis of said second pair of plugs being disposed parallel to each other and substantially perpendicular to said one surface of said secondplate, the opposite surface of said second plate being curved and forming with said opposite surface of said first plate arcs of a continuous curve, a

secondhollow sleeve for each of said second plugs and connected thereto and extending from said opposite surface of said second plate, a second pair of leads each having one end thereof received in one of said second sleeves, said second sleeves being crimped about the associated second leads to form .a mechanical and electrical connection therewith, and a connector electrically interconnecting the other ends of all of said leads.

19. A shunt for use with carbon brushes having two spaced apart holes therein and useful in motors and generators, said shunt comprising a plate, a first plug mounted upon said plate and extending from one side thereof, a second plug mounted upon said plate and extending from said one side thereof and spaced away from said first plug, said plugs being insertable in and removable from the holes in an associated carbon brush and when inserted therein making electrical contact therewith, a first flexible lead having one end thereof connected to said first plug and extending from the other side of said plate, a second flexible lead having one end thereof connected to said second plug and extending from said other side of said plate, and a connector electrically and mechanically interconnecting the other ends of said leads.

20. A shunt as set forth in claim 19, wherein each plug is provided with a hollow sleeve connected thereto and extending from the other side of said plate and receiving the associated lead and being crimped thereabout to form said first pair of plugs and extending from the other side of said first plate, a second plate, a second pair of plugs mounted upon said second plate in spaced apart relation and extending from one side thereof, a second pair of leads each having one end thereof connected to one of said second pair of plugs and extending from the other side of said second plate, said plugs being insertable in and removable from the holes in the associated carbon brushes and when inserted in said holes making electrical contact therewith, and a connector electrically and me chanically interconnecting the other ends of all of said leads.

22. A shunt as set forth in claim 21, wherein each plug is provided with a hollow sleeve connected thereto and extending from the other side of said plate and receiving the associated lead and being crimped thereabout to form a mechanical and electrical connection therewith.

References Cited in the file of this patent UNITED STATES PATENTS 1,010,118 Crouse Nov. 28, 1911 1,017,285 Deviese Feb; 13, 1912 1,255,119 Slick et a1. Jan. 29, 1918 1,351,059 Newberry Aug. 31, 1920 1,441,640 Taylor Jan. 9, 1923 1,579,097 Erdman Mar. 30, 1926 1,844,174 Munday Feb. 9, 1932 2,634,344 Robinson et a1 Apr. 7, 1953 FOREIGN PATENTS 227,453 Great Britain Apr. 1, 1926 

